What to know about the investigation into Nancy Guthrie’s disappearance

A glove containing DNA found a couple of miles from the Arizona home of Today show host Savannah Guthrie ’s missing mother appears to match those worn by a masked person outside her house the night she disappeared, the FBI said on Sunday.

The development comes as law enforcement gathers more potential evidence in the search for Nancy Guthrie, 84, which heads into its third week.

Nancy Guthrie was last seen at her home in Tucson, Arizona, on January 31 and was reported missing the following day.

Authorities say her blood was found on the front porch. Purported ransom notes were sent to news outlets, but two deadlines for paying have passed.

Authorities have expressed concern about Nancy Guthrie’s health because she needs vital daily medicine.

She is said to have a pacemaker and have dealt with high blood pressure and heart issues, according to sheriff’s dispatcher audio on broadcastify.com.

Here is what to know about her disappearance and the search to find her:

– Video of masked man and discovery of a glove

The FBI on Tuesday released surveillance videos of a person wearing a handgun holster outside Mrs Guthrie’s front door the night she vanished. A porch camera recorded video of the person with a backpack who was wearing a ski mask, long trousers, jacket and gloves.

On Thursday, the FBI called the person a suspect. It described him as a man about 5ft, 9in tall with a medium build. The agency said he was carrying a 25-litre Ozark Trail Hiker Pack backpack.

On Sunday, the FBI said in a statement that a glove, found in a field near the side of a road about two miles from the home, had been sent off for DNA testing.

The agency said that it received preliminary results on Saturday and was awaiting official confirmation.

Late Friday, law enforcement agents sealed off a road about two miles from Mrs Guthrie’s home as part of their investigation. A series of sheriff’s and FBI vehicles, including forensics vehicles, passed through the roadblock.

Investigators also tagged and towed a Range Rover from a nearby restaurant car park. The Pima County Sheriff’s Department said the activity was part of the Guthrie investigation.

– Studying DNA

Investigators collected DNA from Mrs Guthrie’s property which does not belong to her or those in close contact with her, the sheriff’s department said.

Evidence requiring forensic analysis is being sent to the same out-of-state lab that has been used since the beginning of the case, the department said.

The FBI has said approximately 16 gloves were found in various spots near the house, most of which were searchers’ gloves that had been discarded.

– Sorting through tips

The Pima County sheriff and the FBI announced phone numbers and a website to offer tips. Several hundred detectives and agents have been assigned to the case, the sheriff’s department said.

The FBI said it has collected more than 13,000 tips since February 1. The sheriff’s department, meanwhile, said it has taken at least 18,000 calls.

The sheriff’s department has not said whether any tips have advanced the investigation.

On Tuesday, sheriff deputies detained a person for questioning during a traffic stop south of Tucson. Authorities did not say what led them to stop the man but confirmed he was released.

The same day, deputies and FBI agents conducted a court-authorised search in Rio Rico, about an hour’s drive south of the city.

– Family pleas

Savannah Guthrie, her sister and her brother have gone on social media and posted video messages to their mother’s purported captor.

The family’s Instagram videos have shifted in tone from impassioned pleas to whoever may have their mother, saying they want to talk and are even willing to pay a ransom, to bleaker and more desperate requests for the public’s help.

A video on Thursday was simply a home video of their mother and a promise to “never give up on her”.

On Sunday night Savannah Guthrie posted an Instagram video in which she issued an appeal to whoever abducted her mother or anyone who knows where she is being kept.

“It is never too late to do the right thing,” Ms Guthrie said. “And we are here. And we believe in the essential goodness of every human being, that it’s never too late.”

– A quiet neighbourhood

Nancy Guthrie lived alone in the upmarket Catalina Foothills neighbourhood, where houses are spaced far apart and set back from the street by long driveways, gates and dense desert vegetation.

Savannah Guthrie grew up in Tucson, graduated from the University of Arizona and once worked at a television station in the city, where her parents settled in the 1970s. She joined Today in 2011.

In a video, she described her mother as a “loving woman of goodness and light”.

She has credited her mother with holding their family together after her father died of a heart attack in 1988 at the age of 49, when Savannah Guthrie, the youngest of three siblings, was just 16.